<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>体验js</title>
  <style>
    .pink {
      color: #ff8500;
    }
  </style>
</head>
<body>
    <button class="pink">按钮1</button>
    <button>按钮2</button>
    <button>按钮3</button>
    <button>按钮4</button>
<script>
  let bts =document.querySelectorAll('button')
  for (let i=0;i<4;i++)
  {
    bts[i].addEventListener('click',function (){
      document.querySelector('.pink').className=''
      this.className='pink'
    })
  }
</script>
</body>
</html>